The Cytogenetics Core is of major significance to the success of Projects 1,2, 3 and the Core C Repository. Its expertise draws on 32 years of experience of the Research and Clinical Cytogenetics Laboratories at Oregon Health Sciences University. These laboratories are recognized internationally for the highest standards of academic cytogenetics excellence. Together, they have a staff of 14 technologists and research associates studying approximately 2,500 blood, bone marrow, solid tumor, amniotic fluid, chorionic villus and other solid tissue samples annually. Through their early efforts of test development, and more recently as the Cytogenetics Core for the current program project grant, these combined laboratories have become a national resource for Fanconi anemia testing.